This invention relates to space heaters and especially to self-powered heaters.
Oil and gas stoves are used extensively for space heating. Many stoves designed for space heating are equipped with electrical components such as blowers for circulating room air and/or bringing in and/or exhausting combustion air. These electrical components are almost always powered by an external electric power source, normally utility power although it is known to power such components using electric power produced by thermoelectric elements driven by heat produced by the stoves.
Long distance truck companies often utilize trucks with sleeping compartments in the truck cab. About three percent of large trucks in the United States are equipped with a space heater operating with diesel or gasoline fuel to provide heat for the cab. The space heaters typically are equipped with electrical components pumping fuel to the space heater, for circulating room air through the space heater and the truck cab and for bringing in combustion air and for exhausting combustion products from the heater. The truck battery provides electric power for these units.
Thermoelectric devices are well known and have been commercially available for about 30 years. One such module is described in U.S. Pat. No. 5,892,656 that is incorporated herein by reference. Its dimensions are 2xc2xd inches X 2xc2xd inches X 0.2 inch and with a temperature difference of 360 degrees F will produce 14 Watts at 1.65 volts.
What is need is a compact self-powered liquid fuel space heater.
The present invention provides a self-powered space heater. At least one thermoelectric module is sandwiched between a hot surface of a combustion chamber of a fluid fired space heater and a room air-cooled heat exchanger for transferring heat from the space heater to room air. A blower circulates room air through the heat exchanger for the dual purpose of heating the room air and also removing heat from the heat exchanger. In a preferred embodiment two thermoelectric modules are utilized in a diesel fuel fired space heater to provide heated air for the cab of a diesel truck. Spherical self-alignment washers are used in a compression frame to apply uniform compression force to both hot and cold sides of the thermoelectric modules. The two modules provide about 25 Watts output that is more than sufficient power to operate the heater that requires about 20 Watts. Extra power can be used for other purposes such as battery charging. The invention is also useful to provide self-power to heaters in vehicles other than truck and other space heaters such as pellet stoves and fireplaces.